The H_GetPerformanceCounterInfo PHYP hypercall has a subcall,
Affinity_Domain_Info_By_Partition, which returns, among other things,
a "partition affinity score" for a given LPAR. This score, a value on
[0-100], represents the processor-memory affinity for the LPAR in
question. A score of 0 indicates the worst possible affinity while a
score of 100 indicates perfect affinity. The score can be used to
reason about performance.
This patch adds the score for the local LPAR to the lparcfg procfile
under a new 'partition_affinity_score' key.
The H_GetPerformanceCounterInfo hypercall is already used elsewhere in
the kernel, in powerpc/perf/hv-gpci.c. Refactoring that code and this
code into a more general API might be worthwhile if additional modules
require the hypercall in the future.
Signed-off-by: Scott Cheloha <chel...@linux.ibm.com>
---
arch/powerpc/platforms/pseries/lparcfg.c | 53 ++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/arch/powerpc/platforms/pseries/lparcfg.c
b/arch/powerpc/platforms/pseries/lparcfg.c
index b8d28ab88178..b75151eee0f0 100644
--- a/arch/powerpc/platforms/pseries/lparcfg.c
+++ b/arch/powerpc/platforms/pseries/lparcfg.c
@@ -136,6 +136,57 @@ static unsigned int h_get_ppp(struct hvcall_ppp_data
*ppp_data)
return rc;
}
+/*
+ * Based on H_GetPerformanceCounterInfo v1.10.
+ */
+static void show_gpci_data(struct seq_file *m)
+{
+ struct perf_counter_info_params {
+ __be32 counter_request;
+ __be32 starting_index;
+ __be16 secondary_index;
+ __be16 returned_values;
+ __be32 detail_rc;
+ __be16 counter_value_element_size;
+ u8 counter_info_version_in;
+ u8 counter_info_version_out;
+ u8 reserved[0xC];
+ } __packed;
+ struct hv_gpci_request_buffer {
+ struct perf_counter_info_params params;
+ u8 output[4096 - sizeof(struct perf_counter_info_params)];
+ } __packed;
+ struct hv_gpci_request_buffer *buf;
+ long ret;
+ unsigned int affinity_score;
+
+ buf = kmalloc(sizeof(*buf), GFP_KERNEL);
+ if (buf == NULL)
+ return;
+
+ /*
+ * Show the local LPAR's affinity score.
+ *
+ * 0xB1 selects the Affinity_Domain_Info_By_Partition subcall.
+ * The score is at byte 0xB in the output buffer.
+ */
+ memset(&buf->params, 0, sizeof(buf->params));
+ buf->params.counter_request = cpu_to_be32(0xB1);
+ buf->params.starting_index = cpu_to_be32(-1); /* local LPAR */
+ buf->params.counter_info_version_in = 0x5; /* v5+ for score */
+ ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO, virt_to_phys(buf),
+ sizeof(*buf));
+ if (ret != H_SUCCESS) {
+ pr_debug("hcall failed: H_GET_PERF_COUNTER_INFO: %ld, %x\n",
+ ret, be32_to_cpu(buf->params.detail_rc));
+ goto out;
+ }
+ affinity_score = buf->output[0xB];
+ seq_printf(m, "partition_affinity_score=%u\n", affinity_score);
+out:
+ kfree(buf);
+}
+
static unsigned h_pic(unsigned long *pool_idle_time,
unsigned long *num_procs)
{
@@ -487,6 +538,8 @@ static int pseries_lparcfg_data(struct seq_file *m, void *v)
partition_active_processors * 100);
}
+ show_gpci_data(m);
+
seq_printf(m, "partition_active_processors=%d\n",
partition_active_processors);
--
2.24.1
